Six male Sprague-Dawley rats were used to examine the long-term retention of an olfactory discrimination learning set. Rats were trained on 30 odor-unique, 5-trial discrimination problems, transferred to an olfactory discrimination reversal task, and then given a 6-week break in training. The rats demonstrated use of a learning set by performing significantly better than expected by chance on Trial 2 on both the olfactory discrimination problems and the olfactory discrimination reversal problems. Following the 6-week break in training, retention of learning set was tested using 20 new odor-unique discrimination problems. The rats again performed significantly better than expected by chance on Trial 2 in the retention test indicating they had retained the learning set. (Contains 3 figures.)